So I started with a desire for a high(er) quality music experience and as I have always liked building stuff (e.g. I have made 2 speaker docks for iPhone), I decided to build my very own Boombox.

First step was to look what others had made and internet is the best place for stealing ideas. Props to SDgeek for great inspiration! After gathering some ideas I set out to find the ingredients for my BoomSoup which are as follows:

- The amp: Pyle PCAU48BT - bluetooth mini power amplifier
- The speakers: JBL CS760C - speaker component set
- 12mm plywood - for construction
- 8mm MDF - for sound dampening
- wood glue - for gluing 'em together ofc
- different types of screws - I really like torx head :)
- wood filler - gotta make it smooth
- paint - obvious
- power cord and a socket for boombox - 'cause the amp came with an undetachable cable and an US plug (I live in EU)

All components were carefully picked out to maximize compatibility and affordability and quality of course.

And as it came out, I made a mistake of getting too powerful speakers for that amp. Therefore always pick an amp that is 1.5 to 2.5 times the power of the speakers you're gonna install! Otherwise problems may occur like I did. I'm not gonna go into details here because i'm still trying to figure out how to solve my issue. But nevertheless sound comes out and its great.

Now let's see how I made it happen in the next step!

Step 1: Break the Amp Apart and First Cuts

What's the first thing to do when you receive something new?
- Break it apart of course!

After seeing the intestines of the amp I started designing the Bbox in CAD. I think I landed on a quite awesome look for it. The conditions were: as small as possible, as cool as possible, as good as possible. I have to mention that I did not design the whole Bbox in CAD from start to finish, only the outer layer. Everything that's inside or at the back was figured out as I progressed through the build. What I had in mind was to use plywood for the outer layer because it's lighter and stronger, and use MDF on the inside for sound dampening.

Time for drawing and cutting.
Started off by drawing the first lines and making the most important cuts - the speaker holes. Used a router and a custom circle cutting jig for it. Another challenge was to get the bottom pieces to fit. After calculating out the necessary angle of the pieces, I set my table saw and made the cuts. Almost a perfect fit. Nothing wood filler can't fix. Having cut out all the pieces I began to assemble them with screws for starters so I can make corrections if needed. Always drill pilot holes for both the pieces you want to attach. I also drilled the screws 2-3 mm into the plywood so I could fill the holes afterwards and get a smooth surface. As for the center console cavity where the knobs will go, I made a template and used the router to carve that out. All smaller holes were cut by hand. The same goes for the tweeter holes.

Having finished with the outer box I cut the MDF pieces into size and tried them in. A perfect fit. ...almost.

Step 2: Dry Fitting the Components

As I had made some errors in my hole cutting for the controls, I decided to make my life a bit easier and cut out the front face pieces from the amp and fit them directly onto my Bbox for an easy installation of components. Being satisfied with the outcome it was time to dry fit the components and see how I would actually attach them to the Bbox. In the meantime I used my tablesaw to cut out the top ventilation slots and a regular jigsaw for corner pieces to attach the power socket, a fuse and a switch to. I desoldered the AV socket from the amp and attached that to the back too. Those corner pieces are also used to fasten the middle backplate. Next I cut out some L-pieces to hold the speakers in place.

All components figured out it was time for a test and it was awesome!!!

Happy with the first test results I dismantled the hole thing and started the assembly again, but this time with glue.
And with glue the whole thing became more massive which means more sound out of the speakers rather than the box itself.

Step 3: Final Touches

As for the middle backplate I wanted it to have an air inlet at the bottom, so I found some old speaker mesh and cut and bent that into size. Attached it with some screws and I have to say, looks fantastic. Meanwhile I had managed to eff up the tweeter holes... I had imagined a 2 mm chamfer on the edges but cutting that with a big 45 chamfer bit did not go so well... spent some big time fixing those holes...

Time for wood filler. Filled out all the screw holes and other abnormalities on the surface of the Bbox. After letting it dry, came the sandpapers turn for action. A lot of sanding went into it for that perfect surface.

At the same time I decided to attach the remote that came with the amp to the back. Used the router again for that nice little hole.

The painting!

As it's in the middle of the winter here I couldn't paint it in minus degrees, but I managed to get the primer on, so as of now it's unfinished from the outside. I'll finish it in the summer.

Step 4: Upgrading

It's summer, so time to finish my project. Story goes as follows.

The amp that I bought unfortunately had no radio function and few months in use, I really wanted it to play radio too. Therefore ebay to the rescue. I managed to find a LCD bluetooth radio player with SD/USB and AUX support. A bit of circuitry and it connected right up with the rest of the amp. As the old player on the amp worked on 5v and the LCD one needs 12v I had to become creative. First I tried to get that 12v off of the amp board itselt (the one with the heatsink), but that caused a lot of interference when using bluetooth. The amp originally had a seperate board for powering the player but that received 9v AC and had an output of 5v DC. But after a bit of tinkering around I managed to get 12v DC out of it. And the interfererence was gone, yay!

Next I took on cutting the boombox face open for the new player. I decided to use a CD box as the new faceplate. That way I had a protective glass for the LCD and it was the easiest to cut neccessary holes into for buttons and USB/SD openings. Glued it in place and filled the edges with filler for a flat surface. And the new player install was complete. Time to sand prime and paint and Voilaa! the boombox is finally finished in red :)

Overall took me about 2 months worth of work with long waiting times in between (waiting for the motivaton to continue my project, oh and also parts). But in the end, I'm very pleased with the outcome and it's blasting music into my house all day long! Also looking good in my room :)

Well thank you for reading, feel free to leave your comments below and good luck on your projects! ;)

Participated in the
Make a Box Contest

8 Comments

Walterf1

5 years ago on Introduction

Nice build, but the instructions ar not clearly laid out. You will have to have some knowlwdgew of assembly and electronics to builsd this unit.

ProgrammingGod

6 years ago

Cool boom box! I am thinking of doing something similar could you post your CAD files?

ewsmith

7 years ago

Great Instructible. Great design! I've been looking for an interesting project to do with my son and I think this is it. But I am a newbie and I do have a few questions..

First, can you describe your speakers, such as where your found or bought them and how you selected them? I'm sure the range in cost/size/quality/power rating is huge. I'm hoping to scavenge some but don't know what to look for. I assume yours are fairly small, high quality speakers. Did they come with the tweaters and do they need to match?

Second, can you go into a bit more detail on balancing the amp to the speakers? Here is my confusion: Your amp puts out 120W on each channel and your speakers peak at 150W. I would think clipping or distortion would happen when you try to drive the speakers with more power than they can handle, not the opposite. If not, clipping would occur all the way from zero to the maximum output of the Amp, right? I always thought that's why most amplifiers can only be turned up about half way, so as not to blow the speakers. What am I missing? Maybe the clipping you describe is something very subtle that only an audiophile would notice or avoid?

I know these questions are very basic; I understand if you don't have time to respond.

Great Instructible though.